试述呼气终末正压通气(PEEP)治疗急性呼吸窘迫综合征
参考答案：
(ARDS)的目的。
PEEP是应用机械的方法，使患者在整个呼吸周期中，其呼吸道的压力均维持在正压的水平，其主要生理作用在于：
(1)使呼气末肺泡保持扩张，增加功能残气量，有利于通气和换气功能。
(2)提高肺顺应性，呼气末正压可防止肺泡萎陷，减轻肺间质水肿，使肺组织顺应性增加。
(3)加压吸气增加肺泡通气量和通气血流比值，增进肺毛细血管与肺泡气的换气效率。
(4)对心血管的影响：PEEP治疗可使平均胸内压升高，静脉回流量减少，心排血量减少。因此，呼气末正压通气要调节在5cmH2O以下，以取得较大心排血量和氧运输量及组织缺氧的缓解。
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| Nobody can be happy all the time. You may become unhappy sometimes.1______, when you fail an exam. Or you may become sad when you lose one of your friends or relatives. It's 2______ to have these feeling. If you don't know how to solve these problems, you may 3______ something from Jeff. Jeff almost went mad when his 4______ was killed in a car accident. He 5______ play soccer or go to the movies with his friends. Instead, he just sat in his bedroom and didn't talk to 6______, even his parents. Jeff felt that the world was unfair. He was quite angry with the driver 7______ his car hit his brother, even though it was an 8______. After a few months, Jeff began to understand it was useless to be angry. Now he still 9______ his brother, but he doesn't hate the driver any longer. He is beginning to talk to his parents and this makes them happy again.He doesn't 10______ in his room by himself any longer. Instead, he goes to the movies or plays sports with his friends and he is feeling better now. | |||
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